internal/sync: warn about incorrect unsafe usage in HashTrieMap
When the HashTrieMap expand method runs out of bits, it can be because
the user mutated a key after insertion using unsafe or similar
in violation of the HashTrieMap invariants.
Adjust the panic message to help triage and debugging by
more directly suggesting unsafe code might be at fault.
CL 694635 is a follow-up change that attempts to detect and
report illegally mutated keys sooner and more precisely.
Updates #74948
Updates #73427
Change-Id: Ib2bca067f0e212b8765c61183f59ac229513a823
Reviewed-on: https://go-review.googlesource.com/c/go/+/694376 Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>